Modding the PS Audio Directstream DAC MK1 and MK2

I would like to continue discussing all the mods we have created for these two DAC's as it seems PS Audio is no longer allowing discussions about them on their forum.

For reference here is a link to the closed discussion.


I'm curious what properties nickel has that gives it an advantage over iron transformers? I still can't believe how much better the PS Audio DSD MKI sounds after replacing the off the shelf transformers with nickel transformers and upgrading the caps. 

Much lower distortion. The nickel is just part of the equation in making a great transparent audio transformer.  We design these specifically for the MK1 or the MK2.  They are not interchangeable.  

Post removed 
Post removed 

It seems the other forum is moving reviews of the Vocm mod and transformers to a members only area of their forum so only members can view them now.


Here is what is being moved to the private area:





Just received and installed JK Richards’ most excellent APS nickel core audio transformers in the Mk1 DAC. Very initial impressions are extremely positive. Have listened to two very familiar Lyle Lovett cuts so more to come later today and this weekend, but I’m really liking what I hear so far.

Also, @jkrichards tip to buy some kind of proper de-soldering station is brilliant. It took me about 5 minutes to remove both Edcor XS4400 transformers and another 10 minutes to solder in the new APS units. DAC powered right up and worked the first time. Yay!


APS DAC Xformers



Update: Thanks to JK Richards for pointing out the need for the Vocm upgrade as part of the nickel transformer swap. Bought a magnifying lamp and discovered I can still handle surface mount parts without too much fuss.

Just finished this and playing some more classic Lyle Lovett. Man this DAC is getting absurdly great.




Yessir. The sound is simply magnificent. Hard to describe the combination of both ease and articulation. Back to that proper place of just enjoying loads of music. A good sign for sure.

My audiophile goal in general is to elevate both my digital and analog front ends to be equal but different. So far so great.




Just received my DAC after the Vocm and APS xformer mod. Read the reviews on this thread and expected an improvement; however, I’ve heard it before and am a tad jaded. I expected a subtle improvement. Whenever, I make a change the first things I put on is the Stereophile Vol 2 Test Cd to verify I didn’t swap channels and phase. As I listen to “The Fender Bass Guitar you are about to hear should appear to come from the left……”, I’m like OMG! The low end authority and inner detail was so obvious. The out of phase test throws an image to the front and right of the right speaker for some reason. This time it is farther forward and to the right and chiseled in granite. Wow, this is really good. A few folks mentioned more bass. I was a tad concerned as it occurred that the software may have been tweaked to make up for the original xformers and with the APG xformers it may be an issue. I thought not a biggie as I can correct. Well after only sitting with this for an hour not on board with the more bass statements. Authority, control, articulation of the low end; yes, absolutely concur, but not larger amplitude. When I get around to doing Room EQ Wizard (REW) sweeps I do not expect to see more bass. So freaking happy. To put this in perspective, IMO this was a bigger upgrade by a wide margin than when I went from Perfectwave MK2 to the DS DAC (aside from going from edge to buttery smooth) from a perspective of detail, soundstage, chiseling of instuments within soundstage, tight grip on low end. Really happy. Thanks Jeff!


last visit



Thanks. I’m happy you are enjoying your new DAC upgrade. This upgrade brings this DAC’s sound quality up to and even surpass the new MK2. Tho The MK2 transformers do make a big improvement in the sound quality for MK2 fans.